Derived (Multi-Valued) Attributes
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These special attributes are configured independently (like Environment Attributes) and become available in the Condition Editor (section Creating a MAC Condition) when successfully configured. Derived Attribute Definitions reside under Administration --> Access Control in the TOC.
Figure 19.
Derived Attributes use an embedded Query Definition to specify the Path from the Root (CurrentItem) to a related Leaf Item and its Target Property from which the Derived Attribute values are extracted.
Refer to the following section for an explanation of Derived Attributes.
Configuring a Derived Attribute
A Derived Attribute has the structure shown in Figure 20 and described in Table.
Figure 20.
Table 6: The Derived Attribute structure
| 1 | Name | Symbol by which this derived attribute is referenced (Required). Enclose spaces in [square brackets] when used in an expression. | ||
| 2 | Datatype | Datatype of values contained in a derived attribute collection (Required). Must match Target Property type, and vice-versa. | ||
| 3 | Description | Text description of Attribute for reference. | ||
| 4 | Attribute Query | A key Relationshiptype that defines how to derive values for this attribute: | ||
| First-time Entry Only | => | “Applied To” Itemtype | The Itemtype that will define the scope of “CurrentItem” in Boolean expressions; also, the Root Item of the Path defined by the Embedded Query Definition. This field is a Required initial entry and becomes read-only once the Path is defined. | |
| Embedded (Not visible) | => | (Query Definition) | Internally stored query definition describing (a) the Path from Root item to Leaf item and (b) Target Property on the Leaf item to derive into the collection (see diagram below). | |
| R/O | => | Leaf Item | The Item at the endpoint of the Query Path. Target Properties are derived from this item. There can only be one Leaf Item in the query path. | |
| R/O | => | Target Property | Name of the Property on the Leaf Item used to derive Attribute values. Type must match Datatype [2]. | |
The Query Definition is accessed by double-clicking the Leaf Item column* of the Attribute Query. The Root item is pre-populated as the Applied To Itemtype. Using the standard QD user interface, define the Path from Root to Leaf Item, and also select the Target Property. On completion, the read-only Leaf Item and Target Property columns will be populated.
Figure 21.
Using a derived attribute in a Boolean expression
Derived Multivalued Attributes are Collections, and the operators described in Table 8 support their use in Condition logic (Boolean expressions). Table 7: Collection operators
| Operator | Description |
| Collection.IsEmpty(<multival attribute>) | TRUE if Collection is empty |
| Collection.Contains(<multival attribute>, value) | TRUE if Collection <multival attribute> contains the value <value> (type) |
| Collection.Overlaps(<multival attribute1>, <multival attribute2>) | TRUE if Collection <multival attribute1> has values in common with <multival attribute2> |